# ECE 476

## ECE 476 - Power System Analysis

### Summer 2020

### Official Description

### Subject Area

### Course Director

### Description

### Goals

The main course goal is to provide students with a complete overview of interconnected power system operation. At the completion of the course students should be able to develop appropriate models for an interconnected power system, and know how to perform power flow, economic dispatch, and short circuit analysis. Students should also be able to write a basic power flow computer program.

### Topics

- Review of 3 phase systems
- Per unit representation
- Transmission line parameters
- Transmission line representation and analysis
- Network matrices
- Power flow
- Symmetrical components
- Sequence networks
- Symmetric and asymmetrical fault analysis
- Transient stability
- Economic dispatch
- Relaying

### Detailed Description and Outline

The main course goal is to provide students with a complete overview of interconnected power system operation. At the completion of the course students should be able to develop appropriate models for an interconnected power system, and know how to perform power flow, economic dispatch, and short circuit analysis. Students should also be able to write a basic power flow computer program.

Topics:

- Review of 3 phase systems
- Per unit representation
- Transmission line parameters
- Transmission line representation and analysis
- Network matrices
- Power flow
- Symmetrical components
- Sequence networks
- Symmetric and asymmetrical fault analysis
- Relaying
- Economic dispatch
- Transient stability

### Computer Usage

One computer project to write a program for load flow on a sample system.

### Topical Prerequisites

- Three-phase systems and phasors
- Differential equations
- Matrix algebra
- Basic understanding of electrical machines and transformers
- Computer programming

### Texts

J.D. Glover, T.J. Overbye, and M.S. Sama, *Power Systems Analysis and Design*, 6th Edition, Cengage Learning.

### ABET Category

Engineering Science: 83% - 2.5 Credits

Engineering Design: 17% - 0.5 Credits

### Course Goals

The main course goal is to provide students with a complete overview of interconnected power system operation. At the completion of the course students should be able to develop appropriate models for an interconnected power system, and know how to perform power flow, economic dispatch, and short circuit analysis.

### Instructional Objectives

A. By the time of Exam No. 1 (after approximately 10 ninety minute lectures), the students should be able to do the following:

1. Understand the concepts of power factor angle, power factor, complex power, and conservation of power. (1)

2. Solve single-phase circuits for the real, reactive, and complex power supplied by, or consumed by any device in the circuit. (1)

3. Use reactive compensation to change a load’s apparent power factor to any specified value. (2) (7)

4. Solve simple three-phase circuits to calculate any system voltage, current, or power. (1)

5. Understand and be able to use per phase analysis to solve simple three-phase systems. (1)

6. Apply concepts from basic electromagnetics to determine the inductance, capacitance, and resistance of three-phase transmission lines, including lines with conductor bundling. (1)

7. Be able to do basic design of transmission lines to specified parameters. (2) (7)

8. Be able to derive the relationships between the voltage and current on a transmission line, and be able to use hyperbolic functions to solve for the voltage or current at any point along the line. (1)

9. Be able to derive the p equivalent model for a transmission line and then use this model to calculate the power flow through a transmission line. (1)

10. Know the limits affecting the maximum amount of power that can be transferred through a transmission line. (1)

11. Understand concern regarding EMF and its possible impact on human health. (4)

12. Be able to derive the voltage and current relationships for an ideal transformer. (1)

13. Know the standard model for a real transformer and understand how winding losses, eddy currents, hysteresis losses, leakage flux, and finite magnetic permeability affect the model parameters. (2)

14. Be able to determine the parameters of the real transformer model from open-circuit and short-circuit test data. (6) (7)

15. Understand the rational behind per unit analysis, and be able to use per unit analysis to solve single- and three-phase circuits. (1)

B. By the time of Exam No. 2 (after approximately 20 lectures), the students should be able to do all the items listed under A, plus the following:

16. Know the four ways to connect three-phase transformers, the strengths and limitations of each, and be able to solve simple three-phase circuits using the different types of transformer connections. (1) (2)

17. Use per phase analysis to solve simple systems with three-phase transformers connected in each of the four ways described in 14. (1)

18. Have basic familiarity with the characteristics of LTC and phase-shifting transformers, and the concept of circulating vars. (1) (7)

19. Know the rational behind the use of constant power and constant impedance load models. (1)

20. Understand the basics of synchronous machine operation and be able to derive the constant voltage behind a synchronous reactance model. (1)

21. Be able to calculate the bus-admittance matrix for a three-phase system consisting of transmission lines, transformers, and capacitors. (1)

22. Be able to formulate the power flow problem and be able to develop a solution algorithm using both the Gauss-Seidel and the Newton-Raphson methods. (1) (2)

23. Be able to write a simple power flow implementing the Gauss-Seidel method. (2)

24. Understand the generator reactive capability curve, and the limitations it imposes on the reactive power output of a generator. (1)

25. Understand the approximations used in the fast decoupled power flow, and be able to solve small systems by hand, using this algorithm. (1)

26. Be able to use a standard power flow program to model a small power system. Be able to solve simple design problems, such as sizing of capacitors needed to correct low bus voltages or generation redispatch to remove transmission line constraints. (2) (6)

27. Understand the use of the input-output curve, the fuel-cost curve, the incremental-cost curve, and the heat-rate curve for modeling generator costs. (1)

28. Understand how the operational costs of thermal, nuclear, and hydro generators are modeled. (1) (7)

29. Basic understanding of the societal impacts of different types of generation, including renewable generation. (4)

30. Setup and solve the economic dispatch problem for a lossless power system with generator minimum/maximum MW constraints. (1)

31. Be able to derive the equations for the economic dispatch problem for a power system with transmission system losses, including the penalty factor values. (1)

32. Understand the need for the use of unit-commitment for longer term generator cost optimization. (7)

33. Understand current issues associated with restructuring in the electricity industry. (4)

C. By the time of the Final Exam (after approximately 30 lectures), the students should be able to do all the items listed under A and B, plus the following:

34. Know the common causes of faults in power systems. (1)

35. Understand the models for generators during a fault and be able to use the models to calculate the fault current at any point in time for a fault applied to the terminal of a generator. (1)

36. Be able to solve for the voltages and current in a network experiencing a balanced three-phase fault at any location. (1) (7)

37. Understand the advantage of using symmetrical components to analyze unbalanced system operation. (1)

38. Be able to convert between phase values and symmetrical-component values. (1) (7)

39. Be able to develop and solve the positive, negative, and zero sequence networks for systems consisting of machines, transmission lines and transformers. (1)

40. Solve for the fault voltages and currents for single line to ground faults, line to line faults, and double line to ground faults. (1)

41. Know the key needs for system grounding; be able to determine grounding impedance. (1) (7)

42. Know the basics of system protection, including the common protection schemes, such as the use of directional relays and impedance relays. (1) (7)

43. Be able to derive the swing equations for a system consisting of a single generator connected to an infinite bus (SMIB). (1)

44. For the SMIB system, be able to use the equal area criteria to determine the critical clearing time for stable operation. (1) (2)